A method for achieving a strong light source, that is, a light source emitting high intensity light includes, for example, a method of concentrating light by using a lens or mirror, a method using a laser beam, a method of increasing energy to a light source to increase the amount of light emitted and the like.
However, the method of concentrating light by using a lens or mirror spatially concentrate light to increase the intensity, requiring a proper spatial volume, that is, for example, a large lens or a large mirror. The method using a laser beam provides a beam emitted, limited in wavelength. The method of increasing energy to a light source, for example, requires an increased voltage or current supplied to a light source, but it is generally difficult for a user to increase the voltage or current supplied to the light source.
Here, a technology called common noise-induced phase synchronization has been proposed, by which a suitable noise is applied to a signal system from outside to synchronize the phases of the signal system (e.g., see Non-Patent Document 1).